1. Field of the Art
The present invention relates to novel ethylene derivatives, and also to agricultural chemicals and agents for preventing the attachment of aquatic organisms containing said derivatives as an active ingredient. The agricultural chemicals as referred to herein include insecticides, acaricides, nematocides, herbicides and fungicides, etc., and are especially pesticides in the field of agriculture, horticulture, stock farming and sanitation. The agent for preventing the attachment of aquatic organisms are chemicals for preventing the attachment of harmful aquatic organisms such as shells and algae to fishing nets, the bottoms of ships, marine equipment such as buoys, marine constructions, circulating water systems in thermal and atomic power plants, inlet channels for heat exchanger cooling water in chemical industry, underwater constructions and reservoirs.
2. Description of the Related Art
For acrylonitrile derivatives, Japanese Patent Application Laid-Open No. Sho 53-92769 discloses the use of 2′-chloro-3-hydroxy-2-(4-phenyl-2-thiazolyl)-cinnamoyl nitrile as an insecticide; and International Patent Application Laid-Open No. WO-95/29591 discloses its use as an aquatic adhesion inhibitor. Japanese Patent Application Laid-open No. Sho 60-11452 discloses the use of 2-(4-chlorophenyl)-3-(3-pyridyl)-3-oxopropionitrile as a herbicide and Japanese Patent Application Laid-open No. Sho 60-11401 discloses its use as a fungicide.
With the long-term use of insecticides and fungicides, recently, some pests have become resistant to chemicals and are often difficult to exterminate with conventional insecticides and fungicides. In addition, some insecticides are highly toxic and are prone to remain long, without being decomposed, to destroy the ecosystem. Accordingly, it is always expected to develop novel, low-toxic and low-persistent insecticides and fungicides.
On the other hand, in order to prevent the adhesion and growth of marine and freshwater aquatics, it is used antifouling coatings comprising organic tin compounds such as bis(tributyltin) oxide or copper compounds such as copper sulfate and cuprous oxide. However, organic tin compounds are highly toxic, though being effective in preventing the adhesion of aquatics, and are especially prone to accumulate in the bodies of fishes and shellfishes. As so promoting the environmental pollution, the use of those compounds is now under legal controls. Copper compounds are widely used in antifouling coatings for inlet channels and for the bottoms of ships. However, like tin compounds, copper compounds contain a copper as a heavy metal. Therefore, the use of copper compounds will bring about the environmental pollution in future, and agents for preventing the attachment of aquatic organisms comprising such copper compounds are not preferred. Under the above-mentioned situation, it has been desired agents for preventing the attachment of aquatic organisms that have few influences on the ecosystem and bring about little secondary pollution.